K7ITM wrote:
John P. wrote, among other things,

"The pattern of how this sinusoidal current varies in both phase and
magnitude is very different in the two cases (standing and traveling
waves), but you need both a phase reference and multiple locations to
see the differences. "

Do you really need the phase reference? Traditionally (since the
beginning of measuring them, and sometimes still today), standing waves
on a uniform transmission line have been measured by finding a point of
minimum amplitude (as measured by voltage, or alternatively by current)
and a point of maximum amplitude, with no reference to phase. In fact,
SWR was reasonably defined as the ratio of max/min amplitudes.
(snip)

What I was trying to say is that to completely see (measure) all the
differences between the current pattern in a standing wave versus a
traveling wave (or any combination of traveling waves of different
magnitudes in opposite directions, with or without losses, especially
when there are discontinuities in the conductor, like loading coils)
those observations would include phase versus position.

In many practical cases, you can infer what you need to know about the
two traveling waves by just taking amplitude measurements, as you suggest.